The present invention relates to an adjusting device for control cables, which is applicable to control cables of the type made up of two control half-cables which can be linked together. More particularly, the present invention relates to an adjusting device for control cables which are habitually used in the automotive industry for the transmission of thrust/traction forces, and which are known as push-pull operating cables. Adjusting devices serve to adjust the length of the sheathed portion of the control cable once it is fitted on the vehicle.
Known in the art are a wide variety of embodiments of control cables such as those mentioned above. Conventionally, control cables comprise an inner steel cable and an outer sheated portion. Each end of the steel cable has a respective steel cable terminal designed for linkage to an actuating control and an actuated mechanism, respectively. The ends of the sheathed portion are provided with respective sheath terminals, one or both of which are attached to fixed points of the vehicle structure.
There are some known embodiments of control cables which are formed by two control half-cables which can be linked together. These embodiments are especially indicated, for example, in cases in which the distance between the actuating control and the actuated mechanism is relatively long or in other cases in which the desired route of the control cable in the vehicle means that it has to be installed in different phases. Adjustment of the length of the sheathed portion is in any case required, in order to make the length thereof suitable for the tolerances presented by each vehicle in respect of tolerances of relative layout between the actuating control and the actuated mechanism.
In cases where the control cable is made up of two linkable half-cables, one possibility is to adjust the length of the sheathed portion of the control cable when making the linkage between the half-cables. Thus, such cables preferably have in the intermediate portion a linking device for the two half-cables, and an adjusting device coupled thereto.
In view of the above, it is the object of the present invention to provide an adjusting device for a control cable, allowing an easy and quick assembly of the control half cables and a convenient way of adjustment of the length of the outer sheated portion of the control cable to the desired length. At the same time, the adjusting device should be easy to manufacture, and thus allow an economic production thereof.
This object is solved by an adjusting device in accordance with claim 1.
In more detail, the present invention provides for an adjusting device for a control cable comprising a first control half-cable and a second control half-cable which are connectable with a linking device, the adjusting device comprising:
a. a male part;
b. a female part complimentary shaped to said male part, said male part being longitudinally insertable into said female part; and
c. locking elements to lock said male part and said female part with respect to each other at a desired longitudinal position.
According to a preferred embodiment of the present invention, the adjusting device is applicable to linking devices of two control half-cables forming a linking control cable between an actuating control and an actuated mechanism. The linking device is of the type made up of two tubular exterior linking bodies, first and second bodies respectively, which can be removably coupled together axially through linking means fitted on their facing ends, or exterior ends, and by two interior linking bodies, first and second bodies respectively, which can be removably coupled together axially through linking means fitted on their facing ends, or exterior ends, with the interior end of a first exterior linking body being attached to one of the intermediate sheath ends, with the interior end of a second exterior linking body being provided with an axial extension which forms a male part or regulating stem of the adjusting device, while the interior ends of the interior linking bodies are attached to respective intermediate ends of the steel cable, the adjusting device comprising:
a. a female part or sheath terminal body of generally long cylindrical shape provided with an axial orifice through which the steel cable of the control cable can slide in both directions, while the terminal body has at one of its ends, the interior end, means for fixing the other intermediate sheath end, the axial orifice being designed to house the regulating stem so that same can slide in both directions;
b. on the regulating stem, an axial orifice through which the steel cable of the control cable can slide in both directions, and to the exterior, some retaining teeth;
c. thrust means which bear permanently upon the regulating stem;
d. fixing means which act upon the retaining teeth of the regulating stem and fix its position on the interior of the sheath terminal body; and
e. leaktightness means to prevent the ingress of liquids, dust, etc., inside the control cable.
The adjusting device according to this preferred embodiment of the invention is characterized in that the thrust means include:
f. a thrust sleeve which is traversed by the steel cable of the control cable, which sleeve has one of its ends, the interior end, attached to the terminal body through respective and complementary coupling means, while at the other end, the exterior end, it is fitted into the axial orifice of the regulating stem, with the exterior end of the thrust sleeve having a perimetral thrust projection;
g. a thrust spring coaxially mounted with respect to the thrust sleeve and working permanently under compression with one of its ends resting against the perimetral thrust projection and its other end against the regulating stem, in such a way that the stem is subjected permanently to a force bearing inwards from the outside; and
h. a handhold piece on the exterior of the regulating stem.
According to another preferred embodiment, the means of coupling of the interior end of the thrust hose with the sheath terminal body may comprise a retaining bushing provided with an axial orifice fixed to the terminal body; and on the interior end of the thrust sleeve, a perimetral retaining projection so designed that the retaining bushing fits between the perimetral retaining projection and the regulating stem.
The mode of operation of the adjusting device according to the above described preferred embodiment of the invention will be now described. Once the steel cable terminals of the control half-cables have been fixed to the actuating control and the actuated mechanism respectively, the sheath ends attached to respective fixed points, and the intermediate ends of the control half-cables attached by means of the linking device, the portion of sheathed steel cable of the control cable is then adjusted by means of the adjusting device of the invention. The adjusting device is supplied ex-works with the thrust spring expanded, that is, with the regulating stem housed to the maximum extent in the axial orifice of the sheath terminal body. In order to adjust the portion of the sheathed steel cable the user holds the sheath terminal body and the handhold of the regulating stem and applies in a longitudinal direction two opposing forces in opposite directions. The application of these forces leads to a simultaneous sliding in opposite directions of the regulating stem and the sheath terminal body, in such a way that the regulating stem is moved from the inside outwards; this sliding of the stem subjects the thrust spring to greater compression by reduction of its length; the sliding of the regulating stem and of the sheath terminal body subjects both sheaths of the control half-cables to compression, and the sliding motion continues until the reactions of the control half-cables are cancelled out by said applied forces, at which moment the length of the sheathed portions is adjusted. Finally, by acting upon the fixing means of the adjusting device, the user fixes the position of the regulating stem, thereby ensuring adjustment of the control cable which is left in the correct service conditions.
The operation of the adjusting device of the invention described above results in the application of forces of opposite direction to the sheath terminal body and the handhold piece of the regulating stem, or which is equivalent, the application of such forces which are compression forces for the corresponding sheaths of the control half-cables, causes the intermediate ends of the steel cables of the control half-cables to move towards each other, and this independently of the route of the control cable, thereby ensuring the union of said steel cables ends, carried out by the control half-cables linking device, during the operation of adjustments of the sheathed portion of steel cable.